﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Wook4_一元二次方程
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                int  d;
                double x1, x2;
                Console.WriteLine("请输入方程ax²+bx+c中a、b、c的值：");
                int a = Convert.ToInt32(Console.ReadLine());
                int b = Convert.ToInt32(Console.ReadLine());
                int c = Convert.ToInt32(Console.ReadLine());
                d = b * b - 4 * a * c;
                if (d >= 0)
                {
                    if (d == 0)
                    {
                        x1 = -(b / (2 * a));
                        Console.WriteLine("方程有且只有一个解,解为{0}",x1);
                    }
                    else
                    {
                        x1 = (-b + Math.Sqrt(d)) / 2.0 * a;
                        x2 = (-b - Math.Sqrt(d)) / 2.0 * a;
                        Console.WriteLine("方程有两个解,分别为{0}和{1}",  x1,x2);
                    }
                }
                else
                {
                    Console.WriteLine("方程无解");
                }
            }
            catch (Exception)
            {
                Console.WriteLine("输入格式有误！");
            }
            Console.ReadKey();
        }

    }
}

